1. Field of the Invention
The present invention relates to a liquid electrophotographic printer, and more particularly, to a photoreceptor belt cleaning apparatus for removing residual developer liquid and foreign matter remaining on a photoreceptor belt used as a photoreceptor medium.
2. Description of the Related Art
In general, in an electrophotographic printer, an electrostatic latent image formed on a photoreceptor medium such as a photoreceptor drum or a photoreceptor belt is developed using developer liquid having a toner mixed with a volatile liquid carrier and is transferred to a sheet, thereby printing a desired image.
Referring to FIG. 1 schematically showing a conventional liquid electrophotographic color printer, a photoreceptor belt 110 supported by a plurality of rollers 121, 122, and 123, circulates around the rollers 121, 122 and 123. The surface of the photoreceptor belt 110 is charged to a predetermined level by a charging station 150. Then, an electrostatic latent image is formed on the photoreceptor belt 110 by a laser scanning unit 130 for irradiating a laser beam onto the photoreceptor belt 110 according to image signals. The electrostatic latent image is developed by a development station 140 for supplying developer liquid. As shown in FIG. 1, in the case of a color printer, a plurality of laser scanning units 130 and a plurality of development stations 140 are provided corresponding to various colors.
Each of the development stations 140 includes a development roller 141, a cleaning roller 142, and squeegee rollers 144 and 146 directly under the photoreceptor belt 110, and accommodates developer liquid 148, in which a toner having a predetermined color and a liquid carrier are mixed, as shown in FIG. 2. Reference numeral 143 represents a developer liquid supplier for supplying developer liquid 148 between the development roller 141 and the photoreceptor belt 110.
The squeegee rollers 144 and 146 remove the excess developer liquid 148 remaining after the developer liquid 148 is utilized for developing the electrostatic latent image. The removed developer liquid is withdrawn into the development station 140 by blades 145 and 147.
The liquid carrier contained in the developer liquid 148 embedded on the electrostatic latent image of the photoreceptor belt 110 is evaporated while passing an image drying station 160 and then only the toner remains, thereby completing the development of the image.
Subsequently, the developed image is transferred to a sheet 126 fed between a transfer roller 124 and a fixing roller 125 via the transfer roller 124, to then be printed. Thereafter, an electrostatic charge remaining on the photoreceptor belt 110 is removed by an erasure station 170.
Here, after the developed image of the photoreceptor belt 110 is transferred to the sheet 126, the toner must be completely removed from the photoreceptor belt 110. However, in the event that the developed image is not perfectly transferred to the transfer roller 124, some toner sludge may remain on the photoreceptor belt 110. Also, foreign matter of the printer may stick to the photoreceptor belt 110 while the photoreceptor belt 110 circulates. The residual toner or foreign matter on the photoreceptor belt 110 may deteriorate the quality of development in repetitive printing procedures, thereby adversely affecting the printing quality of the image.